1. Field of the Invention
The present disclosure relates generally to electrical interconnects, and more particularly to electrical interconnects for ice protection system heater elements.
2. Description of Related Art
Ice can accumulate on exposed surfaces of aircraft during operation in icing conditions, potentially changing aircraft handling qualities and performance. Some aircraft include ice protection systems for selectively heating portions of the aircraft surface to avoid ice accumulation or remove accumulated ice. Such systems generally include resistive heating elements arranged over aircraft surfaces that can be subject to icing, such as rotor blades. Interconnects typically couple each heating element to a power supply through bus segments that extend from the system power supply to the heating elements.
Rotor blades can include one or more heating elements arranged between the blade root and blade tip. Since blade tips can have a relative complex geometry, blade tips are generally constructed as a separate assembly that is attached to the main blade portion during blade assembly. In blade tip assemblies having integral heater elements, an electrical interconnect is generally necessary to couple to the heater element to the ice protection system power supply. Such interconnects are typically constructed from wire or wire braid, and electrically connect the tip assembly heater element to the main blade assembly bus. Wire or wire braid thickness (gauge) selection balances the requirements for low resistivity and flat blade surface contour, larger wire cross-sectional areas having lower resistivity but tending to form a high spot of the blade surface that can lead to mechanical separation or electrical failure during service. Balancing the competing needs of low resistivity and interconnect becomes more difficult when heater elements are connected in series as the interconnect need be sized to handle all the current traversing the heater element bus.
Conventional electrical interconnects have generally been considered satisfactory for their intended purpose. However, there is still a need in the art for interconnects that are electrically efficient and which do not induce discontinuities into the blade surface. There is also a need for interconnects that can carry as much current as the heater element or group of heater elements without generating excessive heat. The present disclosure provides a solution for these problems.